Question

what is the principle in physics used by a ballet dancer and a ice skater?

Answer 1

plz mark answer as brainliest
Dancing is one of the most difficult, disciplined,
and beautiful art forms. Ballet is truly the
foundation of all dance. Ballet teaches self-
discipline, correct body placement, strength, and
gracefulness. Who would guess that ballerinas are
actually physicists in disguise. Not too many
people, but in a way they are because they are
showing us many fundamentals of this science,
which allow them to produce breathtaking, dance
masterpieces. They are performing physics at its
best as they dance, leap and turn across the stage.
Dancing is a unique art form, which lets one
express their feelings and use their body's
capabilities to full extent. In order to use their body
and withhold their own kinesphere, the
fundamentals of mechanical physics are needed to
ensure that the art form is definitely an amazing
one.
The concepts of the following:
• center of gravity and balance
• rotational mechanics and the pirouette
• friction and the glissade
• projectile motion and the grande jete
all are part of physics that underlies the
movements of ballet.
This article discusses how steps in Ballet are
reliant and dependent on mechanical physics.
Looking at dance from the mechanical physics
point of view brings the art form of dance to a
deeper level and shows the enormous amount of
discipline needed to attain a beautiful, talented
ballerina.
Center of Gravity and Balance
Dance consists of movements of the body
interspersed with motionless poses. Often these
poses demonstrate balance of the body over a
small area of support on the floor. Physically, a
condition of balance exists if the dancer remains
motionless above the area of support and does not
fall. The balance condition will be achieved if and
only if the center of gravity lies on a vertical line
passing through the area of support at the floor.
If the dancer is motionless, the sum of all the
forces and torques acting on the body must be
zero. The force of gravity vertically downward will
be balanced by the force upward from the floor to
the foot (the Normal force), acting on the same
vertical line.
This concept is derived from Newton's Third
Law of Motion (the action-reaction law) which
states: Whenever one body exerts a force on a
second body, the second body exerts an oppositely
directed force of equal magnitude on the first body.
If the center of gravity is not in line with these
other equilibrium state forces, the dancer will
be unbalanced and experience an angular
acceleration towards the ground (in other words
the dancer will fall to one side.
A dancer seldom achieves a true balance
condition. If the center of gravity is close to that
“balance area” that is if the forces are almost but
not perfectly vertical, the acceleration away from
vertical is initially quite small and the dancer
appears to be balanced.
Rotational Mechanics and the Pirouette
Turning movements are common in all forms of
dance. One of the most common turns is the
pirouette. The pirouette, in general, is a rotation
where the dancer supports herself on one leg while
the other leg is in retire position. Any pirouette
must commence with some form of preparation
position followed by a torque exerted against the
floor. This torque of the floor against the dancer
causes the angular acceleration that produces
turning motion.
The torque to initiate a turn can be exerted
against the floor by two feet with some distance l.
In Ballet, pirouettes are commonly done from one
of two positions, fourth position or fifth position. A
turn from fifth position, which has a smaller
distance (I), will require more force to produce the
same torque than a turn from fourth position,
which has a larger distance (I). This is because
Torque (T) is equal to the force (F) multiplied by the
distance of the lever arm (l).
Another way to describe the torque used in a
pirouette is to take into account the dancer's
Moment of Inertia. The moment of inertia depends
on the mass of a body and its distribution relative